The present invention relates to a device for instantaneous decimal credibility check for data acquisition terminals or for any data processing or remote data processing apparatus fitted with numerical key board.
Up till now, this problem has been resolved only for the case of treatment by "lots," the check being carried out either by double striking by two different operators, or by the preliminary addition of the movements of data to be checked and the formation of checking totals or sub-totals, or again by "pre-ventilation" consisting of breaking down, in advance, each movement into its constituent elements (for example: total sum, net sum exclusive of taxes and taxes) and of carrying out the check by null proof.
However, where isolated movements (a gate transaction for example) are involved and/or movements to be subjected to instantaneous treatments (in real time), none of the conventional methods indicated above can be applied, and it is only possible to carry out a capacity overload check, with the result that all the data comprised between zero and the maximum capacity of the operand provided by the program are acceptable. This results in a high risk of error, with the annoying and troublesome consequences which this implies, the strongest perturbations arising from errors in the decimal point, that is to say the shifting of the decimal point (real or virtual).
With the continuing extension of computers operating in "real time" or "instantaneous mode", it is becoming of primary importance to be able to eliminate this type of error.
The present invention has as its objective the provision of a device enabling the operator of a terminal to send out, using this terminal, "movements" having a decimal value which has been checked in advance.